GEOHALO

enviscope GmbH and Gomolzig Flugzeug- und Maschinenbau GmbH (GFM) accomplished the entire certification program for airworthiness and integrated the GEOHALO instrument components into the research aircraft HALO operated by DLR. The accompanying certification documents enabled the DLR Design Organization to embed all modifications easily into the “GEOHALO Mission” cabin layout.For this geodetic and geophysical measurement campaign a total of four racks and two gravimeters have passed the design and qualification process and have been integrated into the HALO cabin. Additionally both underwing stations (“PMS- Carrier”) were equipped, each with a scalar and a vectorial magnetometer. A laser altimeter was mounted above a downward looking optical window. A total of eight GPS-Antennas have been installed on different mounting plates.

Beside the measurements of earth potential fields (aerogravimetry and aeromagnetics), one of the experiments was dedicated to prove “GNSS-Reflectometry and Radio Occultation” on aircraft, which is based on accurate analysis of GPS signals passing through the atmosphere or being reflected off the earth’s surfaces. This technique may offer new cutting edge applications like the determination of vertical humidity profiles, sea surface altimetry, or surface wind speed and direction deduced from sea surface roughness. It requires GPS/GNSS antennas in nadir, zenith, and horizontal direction.

In order to facilitate comparable modifications in the future, enviscope/GFM obtains a certification envelope for the “HALO Aperture Mounting Provisions (HAMP)”. In cooperation with the German airworthiness authorities “Luftfahrt Bundesamt (LBA)” the modification has been accomplished with a Supplemental Type Certificate (STC). It covers the implementation of sensors in 10×7” and 10×14’’ apertures as well as the 17’’ side window including the structural adaption to the fuselage by a “retainer”.

From the very beginning of this project enviscope and GFM accompanied the different scientific institutions in instrument design, manufacturing, and documentation in order to obtain the certification. Now, we can proudly record that the complex process has been finished in time. The GEOHALO experiment, the very first scientific campaign with the new research aircraft HALO, has been started as scheduled. We thank our customers (TU Dresden, GFZ, DLR, BGR, IEEC/CSIC) and all involved parties, especially the LBA and both Design Organisations of DLR and GFM for the good collaboration.